The statements in this section merely provide background information related to the present disclosure and may not constitute prior art.
Push button switches are commonly used in many applications for making a contact in an open circuit on a printed circuit board. Such applications are employed on radio controls and vehicle climate controls in vehicle applications and can also be employed in home appliances and other types of equipment. In one design, as shown in FIGS. 10 and 11, a plastic push button 100 is mounted to a housing or bezel 102 and engages a knob 104 that is mounted to a printed circuit board 106. The knob 104 is typically formed as a part of a keypad base 114 that can be made from liquid silicone rubber or other elastomeric material. The keypad base 114 is secured to the printed circuit board 106 by a retaining plate 108. The knob includes a conductive rubber disc 110 mounted to its lower surface opposite to an open circuit 112 disposed on the surface of the printed circuit board 106. The knob 104 includes a generally conically shaped web portion 116 also made from an elastomeric material such as liquid silicone rubber. The knob 104 and web portion 116 can be integrally formed with the keypad base 114. As illustrated in FIG. 11, the knob 104 can be depressed via actuation of the button 100 to cause the web portion 116 to buckle and allow the conductive rubber disk 110 to contact the open circuit contacts 112 on the printed circuit board 106.